i actually just came across a book that was published in 2009 that explains variations in dissociation that seems very interesting (although a bit expensive). i read a bit of it on google, and it really explains the differences between normal ego states and then the spectrum going up to actual DID and also talks about DDNOS-1, 1a, DDNOS-2...or however it works. it was based on the DSM V.

it is called Dissociation and the Dissociative Disorders: DSM-V and Beyond if anyone else is interested. i definitely am going to get a copy as it would probably help me a lot.

i have read other ones including the stranger in the mirror (the first book i read on dissociation which helped somewhat back then). but that ones sounds incredibly useful.